Model Output Discussion 18z 28/07/13

[Captain Shortwave]

been on here 8 years now i believe...gotta say, this summer has been the best (since at least 06) for people contributing to this thread... it often went without a post for several days in recent summers, so a big WELL DONE! to everyone whos posted here, especially the regulars, who have kept this forum alive and interesting this summer!

I'm glad I didn't say back in June something along the line of "if this summer turns out to be good, I'll eat my hat"

I probably would have ended up having a 3 course meal by September 

[shedhead]

been on here 8 years now i believe...gotta say, this summer has been the best (since at least 06) for people contributing to this thread... it often went without a post for several days in recent summers, so a big WELL DONE! to everyone whos posted here, especially the regulars, who have kept this forum alive and interesting this summer!

Bottom line as always in here is the more interesting the weather the more posts/posters you'll see.  Several of us have posted regularly across the summer to date regardless of the synoptics, but many simply joined in during July when it was hot, much as they do in winter when it's cold...that's just how this place rolls, like it or lump it.

 

The one thing I have noticed this Summer however is how largely peaceful it has been in here, despite some diametrically opposing view at times, so let's hope the same can be said as we roll on into Autumn/Winter.

Edited August 13, 2013 by shedhead

[johnholmes]

another top post cheers Frosty mixed to start hopefully better later,itl be nice for the kids to finish the school hols on a warm and hopefully sunny note

 

John H are we getting there

 

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/test8.gif

 

im still learning and taking on board your posts(i know you also say a few days running with them showing the same kind of picture),atm there appears to be ridging more so(ish) on the ECM?

 

also i notice you posted the other day ref to these...

 

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

 

you mentioned "The anomaly part of the charts shows nothing of any substance near the UK, 30DM is neither here nor there",i was just curious to what 30DM means?...

thanks John

30dm is the anomaly at 500mb in the area shown over the long term average for contour heights in the place shown. The anomaly feature can be pretty misleading and it is that part especially that needs at least 3 days to see if the anomaly, be it -ve or +ve is increasing. In terms of +ve heights it also needs to be shown to develop much in the same place as the 500mb flow is shown to be expected to develop a ridge. It is pretty complex but if you allow about 3 days to see if the ridge/trough remains in a similar place and the +/- height anomalies also fit there and are shown to increase then the upper air pattern on about 70% of occasions will be quite similar to the prediction. This is the product of 3 or more years of following them every day when at home and sometimes while on holiday. They will at times show little, indeed no resemlance, to the 2x or 4x daily synoptic ouputs from any of the main 3 (Met, GFS or ECMWF) even at the T+144 time frame (as far as UK Met go) but they rarely give a less accurate prediction of the upper flow. That is only part of the equation though. The most difficult bit, and always has been, (even prior to computers when human only charts went out to T+24), is the bottom 18,000ft. IF the synoptic pattern shows a similar upper air pattern (look on the Net Wx 500mb outputs) as the 500mb anomaly at 6, 8 or 10 days then you can give reasonable confidence to the synoptic pattern. So the surface isobars will be about right in those cases and even the temperatures will be reasonable (at any rate to me, say +/- 5C over what actually occurs) but the will it rain/snow/when/where/how much remains a major issue with all the models on a day to day basis. Even at T+24 or 12 at times the amount/time/where can be not that good.

Sorry a long post but hope that helps you and others fairly new to the fascinating hobby called meteorology!

Edited August 13, 2013 by johnholmes

[legritter]

Its brilliant to come on this forum and find so much information charts data little bits of interesting modell related articles .im still pretty dosed up with drugs after my op 2 wks ago but lost over 20ib so my wife as said i can have new computer ,so hopefully once iv mastered windows 8 i too can put in some technical stuff [in time perhaps for our winter punch up and IMBY bantering ].on todays modells it does look like after this weekends low we could get another warm spell but still at this range any high pressure and its location will be the big factor ,but it would be nice to see another warm spell to take us to the end of august .

[mushymanrob]

It has left me feeling completely underwhelmed if I'm honest. It's all good and well for the people who had the insane heat then some cracking storms to cap it off but we haven't here. Just not felt motivated to post at all.

 

i was praising those who have contributed, not the weather, this place in summer has been like a dessert before, and due to the likes of frosty, gavin, shedhead, captain shortwave and others model discussion has been interesting and without the ridiculous ramping that some seem to love in winter.

 

the gfs 12z.... wow! best run yet? it might not have the high uppers of previous runs but it has the 10c isotherm over most of the country for longer...

 

nice to see the ukmo 12z now showing high pressure to our south early next week (now its in range).

Edited August 13, 2013 by mushymanrob

[Summer Sun]

Good agreement on the 06z ensemble for a warmer spell to develop from around mid next week

 

 

Looks like the further north you are the cooler it could be

 

UKMO is now moving to a settled outlook with high pressure starting to build to the south

 

[Captain Shortwave]

i was praising those who have contributed, not the weather, this place in summer has been like a dessert before, and due to the likes of frosty, gavin, shedhead, and others model discussion has been interesting and without the ridiculous ramping that some seem to love in winter.

 

the gfs 12z.... wow! best run yet? it might not have the high uppers of previous runs but it has the 10c isotherm over most of the country for longer...

 

nice to see the ukmo 12z now showing high pressure to our south early next week (now its in range).

Yeah pretty much, the pressure build is quicker on this afternoons GFS meaning the heat comes in during high resolution.

Northern areas would have a slower start with that shortwave still present. But any rain from fronts would weaken significantly as pressure builds and pretty much destroys that little low.

 

The pressure build is starting to get into the realms of the UKMO time frame, so we will have another model to look at with respect to how things go.

Edited August 13, 2013 by Captain shortwave

[mushymanrob]

Yeah pretty much, the pressure build is quicker on this afternoons GFS meaning the heat comes in during high resolution.

Northern areas would have a slower start with that shortwave still present. But any rain from fronts would weaken significantly as pressure builds and pretty much destroys that little low.

 

The pressure build is starting to get into the realms of the UKMO time frame, so we will have another model to look at with respect to how things go.

 

trouble is, that little low, a shortwave expected to form on that cold front (seen on the fax) would be a cloudy spoiler, so we might get warm uppers but with cloud itll just be muggy. until it clears

 

 

assuming it forms anyway! :lol:

[Cheshire Freeze]

i was praising those who have contributed, not the weather, this place in summer has been like a dessert before, and due to the likes of frosty, gavin, shedhead, captain shortwave and others model discussion has been interesting and without the ridiculous ramping that some seem to love in winter.

 

 

 

Fair dos but on the instances I've looked in here the posting has been heavily biased towards seeking out high pressure. I don't know if you can remember or not but I did start offering my thoughts until the usual bile was directed towards me by a couple of members who took the hump over suggestions the heat would break down later in July and into August. That was enough to put me off from posting. I've stated a couple of times bias doesn't come into my thoughts in the slightest. As you say, however, kudos to those who have provided an unbiased analysis of model output over the last few weeks.

 

Looks like a nice burst of late summer settled weather coming up, in the 168+hr time frame. Will suit a lot of people down to the ground I'm sure

Edited August 13, 2013 by CreweCold

[DTHFCJ]

30dm is the anomaly at 500mb in the area shown over the long term average for contour heights in the place shown. The anomaly feature can be pretty misleading and it is that part especially that needs at least 3 days to see if the anomaly, be it -ve or +ve is increasing. In terms of +ve heights it also needs to be shown to develop much in the same place as the 500mb flow is shown to be expected to develop a ridge. It is pretty complex but if you allow about 3 days to see if the ridge/trough remains in a similar place and the +/- height anomalies also fit there and are shown to increase then the upper air pattern on about 70% of occasions will be quite similar to the prediction. This is the product of 3 or more years of following them every day when at home and sometimes while on holiday. They will at times show little, indeed no resemlance, to the 2x or 4x daily synoptic ouputs from any of the main 3 (Met, GFS or ECMWF) even at the T+144 time frame (as far as UK Met go) but they rarely give a less accurate prediction of the upper flow. That is only part of the equation though. The most difficult bit, and always has been, (even prior to computers when human only charts went out to T+24), is the bottom 18,000ft. IF the synoptic pattern shows a similar upper air pattern (look on the Net Wx 500mb outputs) as the 500mb anomaly at 6, 8 or 10 days then you can give reasonable confidence to the synoptic pattern. So the surface isobars will be about right in those cases and even the temperatures will be reasonable (at any rate to me, say +/- 5C over what actually occurs) but the will it rain/snow/when/where/how much remains a major issue with all the models on a day to day basis. Even at T+24 or 12 at times the amount/time/where can be not that good.

Sorry a long post but hope that helps you and others fairly new to the fascinating hobby called meteorology!

Many Thanks John for taking the time to reply and with a top post to boot,o dear i have a lot of learning to do,no wonder the other day you was puzzled by my post(#676)dont blame you...il continue to learn just like many on here.

Thanks again

sorry for off topic.

Edited August 13, 2013 by DTHFCJ

[J10]

To me it has become plume watch over the last couple of weeks.

 

Overall charts not too bad again tonight, pressure definitely establishing itself from the south.

[Frosty.]

Fair dos but on the instances I've looked in here the posting has been heavily biased towards seeking out high pressure.

 

There has been plenty of heavily biased posts towards seeking low pressure too, don't forget that bit!

[Cheshire Freeze]

There has been plenty of heavily biased posts towards seeking low pressure too, don't forget that bit!

 

Oh yes both sides have had their moments!

[Frosty.]

A much more settled Gfs 12z run which is more reflective of the mean compared to the 6z which was a cool and unsettled outlier, especially when the latest met office update is saying this:-

 

A gradual change to more settled weather is expected thereafter, Southern and eastern areas show signs of becoming warmer and more settled around the middle of next week. Towards the end of the month, these generally settled conditions may well extend across much of the UK and temperatures should become warm, locally very warm across parts of England and Wales.

 

The Gfs 12z looks generally settled from early next week through to the end of the run with high pressure cells slowly drifting around and over the uk with temperatures generally in the mid 20's celsius for the south of the uk, nearer low 20's c for the north, very nice and fine and always the chance of tapping into hot continental air if high pressure becomes centred to the east or southeast of the uk, these are excellent charts for those of us wanting one last settled spell before official summer ends, looks like we are going to get it. 

[mushymanrob]

Fair dos but on the instances I've looked in here the posting has been heavily biased towards seeking out high pressure. I don't know if you can remember or not but I did start offering my thoughts until the usual bile was directed towards me by a couple of members who took the hump over suggestions the heat would break down later in July and into August. That was enough to put me off from posting. I've stated a couple of times bias doesn't come into my thoughts in the slightest. As you say, however, kudos to those who have provided an unbiased analysis of model output over the last few weeks.

 

Looks like a nice burst of late summer settled weather coming up, in the 168+hr time frame. Will suit a lot of people down to the ground I'm sure

true we have been looking for heat, but its all been pretty sober and chart supported, unlike winter when hopecasting and fantasy rule.

[johnholmes]

Many Thanks John for taking the time to reply and with a top post to boot,o dear i have a lot of learning to do,no wonder the other day you was puzzled by my post(#676)dont blame you...il continue to learn just like many on here.

Thanks again

sorry for off topic.

 

I apologise for being a bit off hand in my reply to that

[Milhouse]

Within the space of 2 days we should see quite a notable pressure rise.

 

An area of 1025mb pressuse is a new arrival on the GEFS mean charts in recent runs.

 

[Summer Sun]

12 ensembles = warm and drier than average from around the 21st onwards with rainfall taking a drop from the 19th onwards

 

[Captain Shortwave]

ECM has pressure building at T144

 

Also it has the shortwave the GFS has been showing so lets see how it deals with this in the next few frames

[Tamara]

ECM has pressure building at T144

 

Also it has the shortwave the GFS has been showing so lets see how it deals with this in the next few frames

Looks like the ECM has picked up on the idea of the shortwave drawing warmer and more humid air in from the south west. It may leave a front straddling the country as it gets stuck in central UK

 

Edited August 13, 2013 by Tamara Road

[Milhouse]

ECM has pressure building at T144

 

Also it has the shortwave the GFS has been showing so lets see how it deals with this in the next few frames

 

It may produce the injection of some warmth from the south as next week progresses. The high pressure certainly starts off with some quite cool air over the UK.

 

Edited August 13, 2013 by Milhouse

[Summer Sun]

Certainly a chance for warmer air to move in again during next week with +10 uppers making there way back in via the south west

 

[Captain Shortwave]

Pretty darn good

 

Wish the uppers were a little higher but the T240 chart should be a cracker.

Don't really know what happened to the shortwave at T192, ECM houdini act perhaps

That will do nicely, high pressure just to our east, 10C uppers for most of the UK

 

If it went out any further, the conditions would only get warmer

Edited August 13, 2013 by Captain shortwave

[ANYWEATHER]

There we go at T168 both ecm and gfs show the shortwave! I really think that this wont be on tomorrows output! Seen this many times before with this scenario  

[Frosty.]

The GEFS 12z mean brings a glorious end to summer 2013, next week soon becoming dry, sunny and progressively warmer from the south as high pressure builds in after the relatively cool and unsettled weekend, the developing fine spell next week could persist until early september because these ens mean charts look very benign with a calm atlantic and the PFJ up near iceland or even further north. These are great charts and there is also a good chance of tapping into hotter continental uppers as time goes on, this run indicates widespread mid 20's celsius and nearer high 20's c, low 80's F across the south/se.